1. Field of the Invention
The present invention relates to a water intake pipe of an ocean thermal energy conversion (OTEC) power plant, and more particularly to a water intake pipe extended into the bottom of a deep sea for pumping and obtaining cold sea water.
2. Description of the Related Art
In the principle of ocean thermal energy conversion, a working medium (such as oxygen) absorbs heat from warm sea water contained in an evaporator to transform into a vapor form, and the working medium in the vapor form is used for driving a turbine to generate electric power, and the vapor of the working medium is transmitted into a condenser, and the cold sea water is used for exchanging heat to condense the working medium in the condenser, and the condensed working medium is returned to the evaporator for further cycle uses.
Since most of the ocean thermal energy conversion devices are large devices, basic equipments required for the heat exchange to suck and obtain deep cold sea water must have a water intake pipe with sufficient length and diameter to be extended into the bottom of the deep sea. With reference to FIG. 9 for a conventional water intake pipe 9, the water intake pipe 9 is formed by connecting a plurality of connecting pipes 90 having a flange disk structure, and such connecting pipes 90 can be made of a rigid material such as steel or a flexible material such as the fabric of a fire hose.
The speed of pumping cold sea water for the electric power generation is up to 100˜1000 m3/sec, but it is difficult to overcome the structure of a water intake pipe made by connecting steel pipes, since the weight is heavy and the cost is high. On the other hand, it is difficult for the water intake pipe made by connecting soft tubes to overcome the water pressure of 80˜100 kg/cm2 in order to pump water at a position of 800 m˜1000 m below sea level and transmitting the water in a relatively long distance. In addition to the difficulty of pumping water from the bottom of the deep sea at a very high water pressure by the water pump installed in a ship 91 at sea surface, so that when the cold sea water is pumped, a pressure is produced to squeeze and deform an internal wall of the water intake pipe 9, and the deformation is most significant at the top of the water intake pipe. Now, the quantity of pumped water may be decreased by the reduced diameter of the water intake pipe 9, and thus some water pumps are installed at the bottom of the water intake pipe in some designs, but issues including the installation, repair and maintenance and practical application of the water pump installed at the bottom of the water intake pipe 9 still require breakthroughs, and thus the conventional design is not adopted in practical applications. Obviously, the aforementioned drawbacks are the main issues of the conventional water intake pipe 9 used for pumping and obtaining the cold sea water, and it is a main subject for the present invention to overcome the foregoing conventional water intake pipe.